First I’d just like to say that it is an honor to be posting in such great company as the chasers here at LSN.
Now that that’s out of the way, let’s dive into Tropical Storm Isaac.
- Models are coming into much better agreement, and the cone of uncertainty is getting smaller. Overnight land interaction with Hispaniola has cause the center of Isaac to reform to the north and west of the island. The general consensus now is that he will spend very little time over Cuba. The center will just skim the western coast. A bulk of the circulation will pass over the mountainous region, and that may hinder development some, but Gulf waters are absolutely steamy in the mid-to-upper 80s. This will easily aid in intensification over the next day or so.
- The National Hurricane Center now believes that Isaac will be a hurricane once he starts impacting the Florida Keys on Sunday evening. The Florida Peninsula could also see some significant rainfall during this. He is then expected to continue his turn to the Northwest and eventually north on Monday and Tuesday.
- Areas in the Florida Panhandle could start feeling the effects as early as Tuesday afternoon as the initial bands start coming ashore.
- Upon final landfall, it is quite likely that Isaac will be a strong Category 2 (winds of 96 – 110mph). There is an outside chance he could be stronger, but most think Category 2 is the most likely scenario. Effects on the immediate coast will be storm surge, wind damage, and flooding. A category 2 hurricane can push a storm surge of 10 to sometimes 20 feet. This means areas at or above 10 feet above sea level on the eastern side of the eye could be at risk of flooding as the storm comes ashore.
- The winds of a Category 2 hurricane are roughly the same as an EF-1 tornado. The difference is these strength winds will batter trees and structures for hours at a time instead of for a few seconds like when a tornado passes. Structural damage is almost guaranteed in the areas that experience the greatest winds. Many trees can be snapped or uprooted in these winds as well.
- The Storm Prediction Center has begun outlining areas where a risk of tornadoes will be occurring should the current forecast track hold. This area stretches from Tampa, to Jacksonville, to roughly Eufaula, to the Alabama and Florida borders. With landfalling tropical systems, there is always an inherent tornado threat due to the friction caused from the spinning winds in the system.
- Aside from the tornado threat, the current forecast track keeps Isaac at hurricane intensity into southern Alabama. Areas within a 100 mile radius from that point could see winds in excess of 80mph or possibly higher depending on the strength at landfall. Widespread power outages and tree/structural damage will be an issue for most of these areas.
- Also with the tornado and wind threat, comes possibly the most dire part of this period. The Hydrometeorological Prediction Center has released their 5-day forecast which includes the rain swath expected to be generated by Isaac.
As you can see from this image, much of the central Florida Panhandle, southeast Alabama, and western and northern Georgia can expect anywhere from 8 inches to over a foot of rain with this system. While drought conditions persist in the areas, getting that much rain in a short amount of time will certainly lead to major flooding problems. The Flint and Chattahoochee Rivers as well as their tributaries are likely to be very swollen once all is said and done.
Brett Adair from LSN will be in place on the coast during this along with, likely, myself. Plan for now is to leave tomorrow evening and get set up before conditions start deteriorating. Tours are available for this. Contact firstname.lastname@example.org for pricing and scheduling. Stay tuned for more information as it becomes available.